Improved apparatus for collecting annular strand packages



Jan. 29, 1963 E. DAVIS, JR

IMPROVED APPARATUS FOR COLLECTING ANNULAR STRAND PACKAGES Filed April 21, 1961 INVENTOR EUGENE LESLIE DAVIS, JR.

ATTORNEY ent 3,075,343 Patented Jan. 29, 1.963

Filed Apr. 21, 1961, Ser. No. 104,756

4 Claims. (Cl. 57-76) This invention relates generally to the field of manufacturing rayon filaments and yarns.

This invention, more specifically, relates to a improved spinning bucket for rayon and a removable cover therefor.

In the spinning of viscose rayon it is frequent practice to collect the yarn by passing it over a power driven roller and into a bucket or pot rotating at high speed wherein the yarn is wound into a package referred to as a cake. The spinning bucket must obviously be constructed of materials which withstand the corrosive action of the acidic spinning bath and must be sufficiently strong to withstand the considerable forces acting thereon. These buckets have customarily been made of laminated resinous materials or of suitable metals. In any case the spinning buckets of the prior art have been of heavy wall construction, usually having rim sections which extend substantially beyond the outer periphery of the body section.

These heavy walled buckets, while satisfactory from a standpoint of strength and durability, occupy considerable space in the bucket compartments some of which space is not utilized due to the projecting outer rim and which might be used for the winding of larger cakes if a lighter construction could be used. It has become particularly desirable in recent years to realize the greater efficiency attendant on the winding of larger packages and it is especially desirable that this be accomplished without costly rebuilding of the spinning machine which would be required to enlarge the spinning bucket compartments.

It is an object of this invention to provide an improved spinning bucket wherein substantially larger cakes of yarn may be wound without enlargement of the bucket compartment.

Another object is to provide a bucket which is economical to fabricate and which is resistant to corrosion from the acidic spinning bath.

A further object is to provide a removable cover for the spinning bucket, the cover being easily placed in position or removed but being firmly retained in position at all operating speeds.

Other objects and advantages will appear hereinafter.

In the drawings:

FIGURE 1 shows the bucket and cover of this invention with the cover in position,

FIGURE 2 shows details of the cover and the retaining clip.

The body of the bucket 1 shown in the drawings is made of high strength aluminum alloy, and is coated with a corrosion resistant material. The bucket in use is mounted for rotation inside a compartment C formed in structure 9. The hub 3 is filled with a corrosion resistant fiber reinforced resin 4 such as a phenol-formaldehyde resin. An annular recess 5 is provided on the inside of the bucket wall at the top adjacent the rim to form, in cooperation with the rim, a groove for the retaining clip 6 which holds the cover 7 in place. A rim of corrosion resistant metal, such as stainless steel, is adhesively secured to the outer body portion and is folded inwardly over the top edge of the body to form the upper edge of the annular cover retaining groove.

In order to permit the maximum size yarn package for a given compartment size and to give lightweight construction it is highly preferable that the walls of the bucket be quite thin. A wall thickness of inch is satisfactory and it is preferable that the thickness should not exceed A inch. The corrosion resistant metal rim should likewise be thin, otherwise the advantages of the thin walled bucket will be lost. A thickness of inch is satisfactory and thicknesses in excess of inch should usually be avoided. v

The corrosion resistant coating for the body section may be one of the various thermoplastic or thermosetting materials which form a strong bond with the surface of the body. Suitable coatings include such resinous materials as polyvinyl chloride, polyvinylidene chloride, alkyd resins, and the final or intermediate condensation products of urea-formaldehyde resins, phenol-formalde hyde resins and melamine-formaldehyde resins. Coatings of these materials may be dried and the coated bucket subjected to heat treatment to bring the resinous material to a plastic and adhesive state and to transform the coatings into a tough film. The preferred coating from the standpoint of long life and good corrosion resistance is a combination coating wherein the bucket is first coated with an epoxy resin followed by a coating of a phenol-formaldehyde resin coating of the type described in US. Patents 2,198,939 and 2,253,235, which is usually applied only to the inside of the bucket. The epoxy resin coating protects the aluminum against attack by acid better than other coatings but is attacked by carbon disulfide in the rayon yarn. This outer coating prevents this attack.

The bucket cover is seated on the top of the metal rim by means of a peripheral flange 10 which overlaps the rim to some degree but the diameter of the flange must not be greater than the diameter of the rim. The retaining clip 6 is held in a peripheral groove in the cover. The clip has several notches 11 in its outer periphery to permit top drainage of coagulating bath since there are no holes in the bottom of the bucket for this purpose. It is provided with upwardly extending finger grips 12 and -13 at the ends to permit compression of the ring sufiiciently to place the cover in position. The finger grips extend upwardly through a cutaway portion 14 at the outer edge of the cover 7. The clip also has an upwardly extending lug 15 positioned opposite the ends to center the clip, the lug being retained in a notch 16 in the cover. The cover should be constructed of lightweight, corrosion resistant, rigid material. Reinforced plastic or resinous materials are best for this purpose. The preferred structure consists of a laminated disc 17 for the lower portion with a fiber reinforced resin upper portion 18 bonded to the lower disc. Reinforced phenolic resins are well suited for this purpose.

The selection of a suitable material for construction of the retaining clip 6 is somewhat critical in that the clip must be corrosion resistant, must be sufiiciently resilient to permit compression of the clip for ease of placement and removal, but at the same time the clip must be sufficiently flexible and spring-like to seat firmly in the shallow retaining groove until the bucket reaches a suflicient speed that centrifugal force comes into play to lock the cover firmly in position, otherwise it may be thrown out with considerable force thus presenting a hazard to those Working nearby. The locking action is the result of frictional forces between the clip and the groove bottom as Well as engagement with the steel rim 8.

Clips made of modified acrylic resins are suitable for this purpose. Clips made of rubber or rubber-like materials are not satisfactory in this regard.

In order to provide for the winding of the largest possible yarn package within a given bucket compartment, it is desirable that the taper of the bucket wall be minimized. Normally, the walls of spinning buckets are uniformly tapered outwardly from the bottom to the top in order to facilitate removal of the cake at the end of the winding operation. The taper is particularly desirable if the cake is to be centrifugally purified in order that the cake be'properly supported in the purification bucket. It has been found that the taper can be minimized by using a compound taper, i.e., providing a taperof less than 1 and preferably no more than /2 in the top half of the bucket while providing a taper of 1 /2 to 2 and preferably about l%" in the bottom half of the bucket. This reduction in taper, particularly in the top half of the bucket, results in an appreciable increase in the size of the yarn package which can be spun.

The spinning bucket and cover of this invention by a critical combination of materials of construction and design provide a durable lightweight bucket which permits the spinning of rayon cakes of substantially increased size in the same space required for the older thick-walled buckets with inset covers. The use of high strength aluminum alloy permits thin wall construction at relatively low cost while the corrosion resistance coating prevents the harmful corrosive action of the coagulating liquid carried by the yarn. In particular, the combination of an epoxy resin coating followed by the disclosed coating prevents attack byhoth the acid and carbon disulfide carried-by the yarn which single coatings do not accomplish. The stainless steel rim, which must be constructed of relatively high grade stainless steel, provides added strength and corrosion resistance at the point where the bucket is most subject to damage. The cover is designed to cooperate with the bucket in providing the desired increase in package size in that it is of relatively thin construction and is seated on the top of the rim instead of being seated below the rim as has been customary in the art. -Irr-addition, the design of the retaining clip is such thatthe cover is retained in place at all operating speeds even though the retaining groovefo-r the clipv is necessarily shallow because of the thin wall construction of the bucket. The laminated lower. portion of the cover provides the necessary'strength to prevent cracking of the cover due to pressure of the yarn package while the fiber reinforced resin used for the upper portion is easily molded to give the'desired shape while providing durability and relatively high strength. By the above combination of features it is possible to increase the size of the rayon package by about 30% without increasing the space required for the bucket. This results in a material saving in labor required in the handling of these packages. In addition, it is found that considerable savings in the purification liquid used in the process are realized since the larger cakes require very little greater volume of the purification solutions than the smaller cakes.

It is understood that the scope of the invention is to be limited only by the following claims:

I claim:

1. An improved apparatus for collecting annular strand packages said apparatus comprising, in combination, a spinning bucket having a closed end and an open end, said bucket rotatably mounted and fitted within a compartment formed in a surrounding solid structure in operation and provided with a closure element for said open end, said solid structure compartment provided with a side wall portion and a transverse end wall portion, said bucket provided with a relatively thin outer wall portion and a relatively thin transverse wall portion forming the closed end thereof, said wall and closed end portions of said bucket formed of thin aluminum coated with 'toughcorrosion resistant resinous material and-closely fitted to said wall and end portions of said compartment, said outer wall portion of said bucket having interior surfaces slightly tapered outwardly from the closed end to the open end of the bucket, said interior surfaces tapered in progressively lesser amounts from said closed end to said open end of the bucket, said closure element and said open end of said bucket provided with centrifugally actuated means for positively locking said closure element to said bucket during rotation of said bucket and closure element, said centrifugally actuated means comprising an annular groove in the bucket wall forming the open end of said bucket and an annular spring element secured in said closure element and mounted for movement into engagement with said groove during rotation of said bucket and closure element.

2. The improved'apparatus of claim 1' in which said annular .groove in-the bucket wall is formed with an outermost wall portion comprising an'annular's'tainless steel'rirn member adhesively secured to the outer portion of the open end of said bucket and folded inwardly over the open end of said bucket to form an inwardly projecting annular abutment, the peripheral surfaces of said closure element, said rim member, and said bucket outer wall portion, for any sectional view taken parallel to the bucketaxis, forming an exterior, profile which lies substantially in a straight-line. v

3. The improved apparatus of claim 2-in which said annular spring element is provided withmanually actuatable means for moving the element into and out of errgagement with said annular groove in said bucket wall.

4. The improved apparatus of claim 3 in which said tough corrosion resistant resinous material comprises an epoxy'resin inner coating and a phenol-formaldehyde resin outer coating.

References Cited in the file of this patent UNITED STATES PATENTS 

1. AN IMPROVED APPARATUS FOR COLLECTING ANNULAR STRAND PACKAGES SAID APPARATUS COMPRISING, IN COMBINATION, A SPINNING BUCKET HAVING A CLOSED END AND AN OPEN END, SAID BUCKET ROTATABLY MOUNTED AND FITTED WITHIN A COMPARTMENT FORMED IN A SURROUNDING SOLID STRUCTURE IN OPERATION AND PROVIDED WITH A CLOSURE ELEMENT FOR SAID OPEN END, SAID SOLID STRUCTURE COMPARTMENT PROVIDED WITH A SIDE WALL PORTION AND A TRANSVERSE END WALL PORTION, SAID BUCKET PROVIDED WITH A RELATIVELY THIN OUTER WALL PORTION AND A RELATIVELY THIN TRANSVERSE WALL PORTION FORMING THE CLOSED END THEREOF, SAID WALL AND CLOSED END PORTIONS OF SAID BUCKET FORMED OF THIN ALUMINUM COATED WITH TOUGH CORROSION RESISTANT RESINOUS MATERIAL AND CLOSELY FITTED TO SAID WALL AND END PORTIONS OF SAID COMPARTMENT, SAID OUTER WALL PORTION OF SAID BUCKET HAVING INTERIOR SURFACES SLIGHTLY TAPERED OUTWARDLY FROM THE CLOSED END TO THE OPEN END OF THE BUCKET, SAID INTERIOR SURFACES TAPERED IN PROGRESSIVELY LESSER AMOUNTS FROM SAID CLOSED END TO SAID OPEN END OF THE BUCKET, SAID CLOSURE ELEMENT AND SAID OPEN END OF SAID BUCKET PROVIDED WITH CENTRIFUGALLY ACTUATED MEANS FOR POSITIVELY LOCKING SAID CLOSURE ELEMENT TO SAID BUCKET DURING ROTATION OF SAID BUCKET AND CLOSURE ELEMENT, SAID CENTRIFUGALLY ACTUATED MEANS COMPRISING AN ANNULAR GROOVE IN THE BUCKET WALL FORMING THE OPEN END OF SAID BUCKET AND AN ANNULAR SPRING ELEMENT SECURED IN SAID CLOSURE ELEMENT AND MOUNTED FOR MOVEMENT INTO ENGAGEMENT WITH SAID GROOVE DURING ROTATION OF SAID BUCKET AND CLOSURE ELEMENT. 